Bananas

Bananas are easy to digest and can help reduce sugar absorption in circulation, making them an ideal pre-workout snack. Don't throw out the peel because Taiwanese nutritionists discovered that it contains not only more potassium but also mood-boosting serotonin and eye-protecting lutein. In a smoothie, use the whole banana, skin and all.

Bananas are nutrient-dense and high in water and carbohydrates, all of which have been demonstrated to help in workout performance and recovery. Bananas have a slightly greater energy content than other fruits, but the calories are mostly carbohydrate-based, making them ideal for replenishing before, during, or after a workout. They're also high in potassium, which can help prevent muscular cramps when exercising. Eating a banana 30–60 minutes before a workout may be the most beneficial way to enhance performance. Meanwhile, combining 1–2 bananas with other carbohydrate sources might help you recover after an exercise or during a longer one.